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New procedure using contour detection

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2EEEB 2021-12-06 00:22:40 +01:00
parent 074678eaa0
commit 3160dcba40
1 changed files with 35 additions and 14 deletions
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49
ocr.py
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@ -6,21 +6,42 @@ import cv2
from PIL import Image from PIL import Image
def process(image): def process(image):
# Read image
img = cv2.imread(image) img = cv2.imread(image)
norm_img = np.zeros((img.shape[0], img.shape[1])) # Convert to single-channel grayscale
# Normalize img_gs = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
img = cv2.normalize(img, norm_img, 0, 255, cv2.NORM_MINMAX) # Binary threshold to get rid of blemishes
# Crop _, img_gs = cv2.threshold(img_gs, 50, 255, cv2.THRESH_BINARY)
img = img[165:-120, 100:-100] # OTSU threshold for contour detection
# Threshold _, thr = cv2.threshold(img_gs, 0, 255, cv2.THRESH_OTSU | cv2.THRESH_BINARY_INV)
img = cv2.threshold(img, 80, 255, cv2.THRESH_BINARY)[1] # Rectangular kernel for contour detection
# Blur rect_k = cv2.getStructuringElement(cv2.MORPH_RECT, (32, 32))
img = cv2.GaussianBlur(img,(9,9),cv2.BORDER_DEFAULT) # Dilation
# Write modified image dil = cv2.dilate(thr, rect_k, iterations = 1)
cv2.imwrite("output/{}_tmp.png".format(image.split("/")[1].split(".")[0]),img) # Finding contours
# Actual ocr in one call conts, _ = cv2.findContours(dil, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
return pytesseract.image_to_string(img) txt=""
# Iterate over found contours and attemt to ocr text within
for cnt in conts:
x, y, w, h = cv2.boundingRect(cnt) # location and size of found feature
if x == 0 or y == 0:
# Do not do anything if the feature is on image edges, expected text is more or less centered
pass
else:
cv2.rectangle(img, (x, y), (x + w, y + h), (0, 255, 0), 2)
# Crop only the text feature with some padding in horizontal direction to help with ocr
txt_ft = img_gs[y:y+h, x:x+w]
try:
# Write image with the detected text bounding box
cv2.imwrite("output/{}_tmp.png".format(image.split("/")[1].split(".")[0]),img)
# Apply blur to remove sharp edges and help with ocr
txt_ft = cv2.GaussianBlur(txt_ft,(5,5),cv2.BORDER_DEFAULT)
# Actual ocr in one call
txt += pytesseract.image_to_string(txt_ft)
except:
# Fail silently, only the emtpy string will be returned
pass
return txt
if __name__ == "__main__": if __name__ == "__main__":
if not os.path.exists("input"): if not os.path.exists("input"):